When a second call is coming in, you will hear a short beep. If finished talking with the first caller, hang up. The telephone will ring and you can answer the second call.
If you wish to place the first caller on hold and answer the second, depress the switch hook or the flash button on your telephone. Wait for dialtone. Press * 4 to place the first caller on hold.
To alternate between two calls: Repeat: depress switch hook or flash button, wait for dialtone, and then press * 4.
To end a conversation while another call is on hold: Hang up. The telephone will ring and you can return to the second caller.